Printed circuit boards for power supplies

ABSTRACT

At least one embodiment of a power supply includes a printed circuit board formed from a plurality of double-sided laminates and a plurality of thermally conductive, electrically insulating pre-preg sheets interleaved with the plurality of double-sided laminates. Each double-sided laminate illustratively includes an electrically insulating core, a first patterned layer of electrically conductive material arranged on a first side of the electrically insulating core, and a second patterned layer of electrically conductive material arranged on a second side of the electrically insulating core opposite the first side. The printed circuit board illustratively further includes a thermally conductive, electrically insulating additive resin filling spaces between the electrically conductive material in both the first and second patterned layers of each of the plurality of double-sided laminates, such that the electrically conductive material and the additive resin together form planar surfaces that contact the plurality of pre-preg sheets.

TECHNICAL FIELD

This application is a continuation of U.S. patent application Ser. No.16/806,058, filed Mar. 2, 2020, now issued as U.S. Pat. No. 10,827,602,the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to printed circuit boards forpower supplies and, more particularly, to printed circuit boards inwhich a plurality of thermally conductive, electrically insulatingpre-preg sheets are interleaved with a plurality of double-sidedlaminates and in which a thermally conductive, electrically insulatingadditive resin fills spaces between electrically conductive material ofthe plurality of double-sided laminates.

BACKGROUND

Heavy copper printed circuit boards, with greater than 2 ounce copper,typically require a large amount of resin to fill the copper removedduring the etching process. The heavier the copper weight, the moreresin is needed. Additionally, separation between copper planes grows asglass carrying the resin creates a thickness between the copper planes.Furthermore, traditional resin in the glass does not have very goodthermal properties. Currently, printed circuit board layouts usesthermal vias, copper planes, and metal substrate printed circuit boardsto remove or distribute heat. Hot spots across the printed circuit boardmay require additional design and process steps to remove heat throughthermal compounds or heat sinks on the components of the printed circuitboard.

As power supplies become smaller due to efficiency gains, thermalperformance and thermal efficiency become more critical. Currently,integrated metal substrate printed circuit boards or metal-backedprinted circuit boards are used to address thermal issues. Additionally,thermal vias are used to pull heat away from the printed circuit board.A variety of thermal compounds or gap fillers are also used to pull heataway from the components on the printed circuit board. These compoundsare used to minimize the hot spots on the printed circuit board.

SUMMARY

According to one aspect of the present disclosure, a power supply isdisclosed. A printed circuit board of the power supply may comprise aplurality of double-sided laminates and a plurality of thermallyconductive, electrically insulating pre-preg sheets interleaved with theplurality of double-sided laminates. Each double-sided laminate of theplurality of double-sided laminates may comprise an electricallyinsulating core, a first patterned layer of electrically conductivematerial arranged on a first side of the electrically insulating core,and a second patterned layer of electrically conductive materialarranged on a second side of the electrically insulating core oppositethe first side. The printed circuit board may further comprise athermally conductive, electrically insulating additive resin fillingspaces between the electrically conductive material in both the firstand second patterned layers of each of the plurality of double-sidedlaminates, such that the electrically conductive material and theadditive resin together form planar surfaces that contact the pluralityof pre-preg sheets.

In some embodiments, each one of the plurality of pre-preg sheetscontacts both (i) the first patterned layer of one of the plurality ofdouble-sided laminates and (ii) the second patterned layer of anotherone of the plurality of double-sided laminates.

In some embodiments, the first patterned layer of one of the pluralityof double-sided laminates may be spaced less than 4 mils from the secondpatterned layer of another one of the plurality of double-sidedlaminates.

In some embodiments, each of the plurality of pre-preg sheets has athermal conductivity greater than 2 Watts/meter-Kelvin.

In some embodiments, the electrically insulating core of each of theplurality of double-sided laminates comprises a cured pre-preg sheethaving a thermal conductivity greater than 2 Watts/meter-Kelvin.

In some embodiments, the additive resin has a thermal conductivitygreater than 0.3 Watts/meter-Kelvin.

In some embodiments, each of the plurality of pre-preg sheets and theadditive resin may provide dielectric isolation of at least 500Volts/mil.

In some embodiments, a thermal performance of the printed circuit boardmay be more uniform than and at least 7 percent more efficient thananother printed circuit board lacking the additive resin.

In some embodiments, the power supply may comprise a quarter-brick powerconverter with greater than 95 percent efficiency.

According to another aspect of the present disclosure, a double-sidedlaminate for fabricating a printed circuit board for a power supply isdisclosed. The double-sided laminate may comprise an electricallyinsulating pre-preg sheet having a thermal conductivity greater than 2Watts/meter-Kelvin, a first layer of electrically conductive materialarranged on a first side of the electrically insulating pre-preg sheet,and a second layer of electrically conductive material arranged on asecond side of the electrically insulating pre-preg sheet opposite thefirst side.

In some embodiments, the electrically insulating pre-preg sheet mayprovide dielectric isolation of at least 1000 Volts/mil.

In some embodiments, the first and second layers of electricallyconductive material are each patterned. In such embodiments, a thermallyconductive, electrically insulating additive resin may fill spacesbetween the electrically conductive material in both the first andsecond patterned layers, such that the electrically conductive materialand the additive resin together form planar outer surfaces of thedouble-sided laminate.

In some embodiments, the additive resin has a thermal conductivitygreater than 0.3 Watts/meter-Kelvin.

In some embodiments, the pre-preg sheet and the additive resin may eachprovide dielectric isolation of at least 1000 Volts/mil.

According to yet another aspect of the present disclosure, a method forfabricating a printed circuit board for a power supply may compriseapplying a thermally conductive, electrically insulating additive resinto fill spaces between patterned electrically conductive materialarranged on a first side of a first electrically insulating core, suchthat the electrically conductive material and the additive resintogether form a first planar surface on the first side of the firstcore, applying the additive resin to fill spaces between patternedelectrically conductive material arranged on a second side of a secondelectrically insulating core, such that the electrically conductivematerial and the additive resin together form a second planar surface onthe second side of the second core, contacting the first planar surfacewith a first side of a first thermally conductive, electricallyinsulating pre-preg sheet, and contacting the second planar surface witha second side of the first pre-preg sheet, the second side of the firstpre-preg sheet being opposite the first side of the first pre-pregsheet.

In some embodiments, the method may further comprise applying energy totransition the pre-preg sheet from a B-stage to a C-stage.

In some embodiments, the first pre-preg sheet has a thermal conductivitygreater than 2 Watts/meter-Kelvin.

In some embodiments, the first and second cores are each a C-stagepre-preg sheet having a thermal conductivity greater than 2Watts/meter-Kelvin.

In some embodiments, the additive resin has a thermal conductivitygreater than 0.3 Watts/meter-Kelvin.

In some embodiments, the first pre-preg sheet and the additive resin mayeach provide dielectric isolation of at least 500 Volts/mil.

In some embodiments, the method may further comprise applying theadditive resin to fill spaces between patterned electrically conductivematerial arranged on a second side of the first electrically insulatingcore, the second side of the first core being opposite the first side ofthe first core, such that the electrically conductive material and theadditive resin together form a third planar surface on the second sideof the first core, applying the additive resin to fill spaces betweenpatterned electrically conductive material arranged on a first side ofthe second core, such that the electrically conductive material and theadditive resin together form a fourth planar surface on the second sideof the second core, contacting the third planar surface with a secondthermally conductive, electrically insulating pre-preg sheet, andcontacting the fourth planar surface with a third thermally conductive,electrically insulating pre-preg sheet.

In some embodiments, the first, second, and third pre-preg sheets eachhave a thermal conductivity greater than 2 Watts/meter-Kelvin and mayeach provide dielectric isolation of at least 500 Volts/mil.

In some embodiments, the additive resin has a thermal conductivitygreater than 0.3 Watts/meter-Kelvin and may provide dielectric isolationof at least 500 Volts/mil.

BRIEF DESCRIPTION OF THE DRAWINGS

The concepts described in the present disclosure are illustrated by wayof example and not by way of limitation in the accompanying figures. Forsimplicity and clarity of illustration, elements illustrated in thefigures are not necessarily drawn to scale. For example, the dimensionsof some elements may be exaggerated relative to other elements forclarity. Further, where considered appropriate, reference labels havebeen repeated among the figures to indicate corresponding or analogouselements. The detailed description particularly refers to theaccompanying figures in which:

FIG. 1 is an illustrative diagram showing a cross-section of adouble-sided laminate according to the prior art;

FIG. 2 is an illustrative diagram showing a cross-section of adouble-sided laminate according to the present disclosure;

FIG. 3 is an illustrative diagram showing a cross-section of thedouble-sided laminate of FIG. 2 after the addition of a thermallyconductive, electrically insulating additive resin;

FIG. 4 is an illustrative diagram showing a cross-section of a printedcircuit board according to the present disclosure, assembled from aplurality of the double-sided laminates of FIG. 3; and

FIG. 5 is an illustrative diagram showing a cross-section of a printedcircuit board according to the present disclosure, assembled from aplurality of the double-sided laminates of FIG. 1 (after the addition ofa thermally conductive, electrically insulating additive resin).

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the figures and will be described hereinin detail. It should be understood, however, that there is no intent tolimit the concepts of the present disclosure to the particular formsdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives consistent with the presentdisclosure and the appended claims.

References in the specification to “one embodiment,” “an embodiment,”“an illustrative embodiment,” etc., indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may or may not necessarily includethat particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. Further,when a particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to effect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described.

In the drawings, some structural or method features may be shown inspecific arrangements and/or orderings. However, it should beappreciated that such specific arrangements and/or orderings may not berequired. Rather, in some embodiments, such features may be arranged ina different manner and/or order than shown in the illustrative figures.Additionally, the inclusion of a structural or method feature in aparticular figure is not meant to imply that such feature is required inall embodiments and, in some embodiments, may not be included or may becombined with other features.

One illustrative embodiment of a prior art double-sided laminate 100,useful in fabricating printed circuit boards for power supplies, isillustrated in cross-section in FIG. 1. The double-sided laminate 100comprises an electrically insulating core 102, a layer 104 ofelectrically conductive material arranged on a side 108 of theelectrically insulating core 102, and a layer 106 of electricallyconductive material arranged on another side 110 of the electricallyinsulating core 102 that is opposite the side 108. In this embodiment,the electrically insulating core 102 may comprise one or moretraditional pre-preg sheets, such as electrical grade glass (e-glass)impregnated with resin. The traditional pre-preg sheet(s) 102 may complywith one or more of the IPC-4101 specifications published by theInstitute of Printed Circuits, which specifications are incorporatedherein by reference.

The double-sided laminate 100 may be formed by laminating each of thelayers 104, 106 to one of the opposing sides 108, 110 of theelectrically insulating core 102 while the electrically insulating core102 is at a B-stage (semi-cured). After the layers 104, 106 are arrangedon the opposing sides 108, 110 of the electrically insulating core 102,the double-sided laminate 100 may be cured. For instance, energy may beapplied to the double-sided laminate 100 to transition the electricallyinsulating core 102 from the B-stage to a C-stage, bonding thecomponents of the double-sided laminate 100 together.

The electrically conductive material of the layers 104, 106 may comprisea metal, such as copper. By way of example, the layers 104, 106 may besheets of copper foil. It is contemplated that other electricallyconductive materials (e.g., carbon nanostructures) could be used to formthe layers 104, 106. One of both of the layers 104, 106 may be patternedto form traces of electrically conductive material separated by spaces(where the electrically conductive material of the layer 104, 106 hasbeen removed). For instance, one or both of the layers 104, 106 may bepatterned using etching, machining, or other patterning techniques knownto those skilled in the art.

One illustrative embodiment of a novel double-sided laminate 200, withimproved utility for fabricating printed circuit boards for powersupplies, is illustrated in cross-section in FIG. 2. The double-sidedlaminate 200 comprises an electrically insulating core 202, a layer 204of electrically conductive material arranged on a side 208 of theelectrically insulating core 202, and a layer 206 of electricallyconductive material arranged on another side 210 of the electricallyinsulating core 202 that is opposite the side 208. In this embodiment,the electrically insulating core 202 may comprise a pre-preg sheethaving a thermal conductivity greater than 2 Watts/meter-Kelvin. It isalso contemplated that the pre-preg sheet 202 may have a thermalconductivity greater than 2.5 Watts/meter-Kelvin, greater than 3Watts/meter-Kelvin, or even greater than 3.5 Watts/meter-Kelvin, in someembodiments. The pre-preg sheet 202 may provide dielectric isolationbetween the layers 204, 206 of at least 500 Volts/mil. It is alsocontemplated that, in some embodiments, the pre-preg sheet 202 mayprovide dielectric isolation of at least 750 Volts/mil, at least 1000Volts/mil, or at least 1500 Volts/mil. For instance, in someillustrative embodiments, the pre-preg sheet 202 may be formed of Tpreg™1KA material, commercially available from Laird Technologies, Inc. Inother illustrative embodiments, the pre-preg sheet 202 may be formed ofTlam™ SS HTD material, also commercially available from LairdTechnologies, Inc.

The double-sided laminate 200 may be formed by laminating each of thelayers 204, 206 to one of the opposing sides 208, 210 of theelectrically insulating core 202 while the electrically insulating core202 is at a B-stage (semi-cured). After the layers 204, 206 are arrangedon the opposing sides 208, 210 of the electrically insulating core 202,the double-sided laminate 200 may be cured. For instance, energy may beapplied to the double-sided laminate 200 to transition the electricallyinsulating core 202 from the B-stage to a C-stage, bonding thecomponents of the double-sided laminate 200 together.

The electrically conductive material of the layers 204, 206 may comprisea metal, such as copper. By way of example, the layers 204, 206 may besheets of copper foil. It is contemplated that other electricallyconductive materials (e.g., carbon nanostructures) could be used to formthe layers 104, 106. One of both of the layers 204, 206 may be patternedto form traces of electrically conductive material separated by spaces(where the electrically conductive material of the layer 204, 206 hasbeen removed). For instance, one or both of the layers 204, 206 may bepatterned using etching, machining, or other patterning techniques knownto those skilled in the art.

Referring now to FIG. 3, the double-sided laminate 200 of FIG. 2 isshown (in cross-section) after the layers 204, 206 have each beenpatterned to form traces of electrically conductive material separatedby spaces. As illustrated in FIG. 3, the spaces between the electricallyconductive material in both the patterned layers 204, 206 have beenfilled with a thermally conductive, electrically insulating additiveresin 300. In some embodiments, the additive resin 300 may have athermal conductivity greater than 0.2 Watts/meter-Kelvin, greater than0.3 Watts/meter-Kelvin, or even greater than 0.4 Watts/meter-Kelvin. Theadditive resin 300 may provide dielectric isolation between the layers204, 206 of at least 500 Volts/mil, at least 750 Volts/mil, at least1000 Volts/mil, or at least 1500 Volts/mil, in some embodiments. Forinstance, in some illustrative embodiments, the additive resin 300 maybe formed of UCP 50A-4 material, commercially available from SAN-EIKagaku Co., Ltd.

As can be seen in FIG. 3, after the spaces between the electricallyconductive material of the patterned layers 204, 206 has been filledwith the additive resin 300, the electrically conductive material of thepatterned layers 204, 206 and the additive resin 300 together formplanar outer surfaces of the double-sided laminate 200. These planarsurfaces are beneficial when assembling a plurality of the double-sidedlaminates 200 into a printed circuit board (as discussed further below),reducing the overall thickness of the printed circuit board, whileimproving its thermal conductivity. The additive resin 300 can beapplied in the same manner to spaces between the electrically conductivematerial of the patterned layers 104, 106 of the double-sided laminate100, such that the electrically conductive material of the patternedlayers 104, 106 and the additive resin 300 together form planar outersurfaces of the double-sided laminate 100.

A printed circuit board (“PCB”) 400 according to the present disclosureis illustratively shown in cross-section in FIG. 4. The PCB 400 isassembled from a plurality of the double-sided laminates 200, amongother components. While the PCB 400 includes three of the double-sidedlaminates 200 in the illustrative embodiment of FIG. 4, it iscontemplated that the PCB 400 may include any number of double-sidedlaminates 200 in other embodiments. The features of the double-sidedlaminates 200 are substantially the same as discussed above withreference to FIGS. 2 and 3 (as such, the component parts of thedouble-sided laminates 200 have not been labelled in FIG. 4 so as not toobscure the disclosure).

The PCB 400 further includes a plurality of thermally conductive,electrically insulating pre-preg sheets 402 interleaved with theplurality of double-sided laminates 200. In this embodiment, each of thepre-preg sheets 402 has a thermal conductivity greater than 2Watts/meter-Kelvin. It is also contemplated that the pre-preg sheets 402may each have a thermal conductivity greater than 2.5Watts/meter-Kelvin, greater than 3 Watts/meter-Kelvin, or even greaterthan 3.5 Watts/meter-Kelvin, in some embodiments. The pre-preg sheets402 may provide dielectric isolation between adjacent layers 204, 206(of different double-sided laminates 200) of at least 500 Volts/mil. Itis also contemplated that, in some embodiments, the pre-preg sheets 402may provide dielectric isolation of at least 750 Volts/mil, at least1000 Volts/mil, or at least 1500 Volts/mil. For instance, in someillustrative embodiments, the pre-preg sheets 402 may be formed ofTpreg™ 1KA material or of Tlam™ SS HTD material, both commerciallyavailable from Laird Technologies, Inc. The plurality of pre-preg sheets402 may be arranged between the plurality of double-sided laminates 200while at a B-stage (semi-cured). After the components of the PCB 400have been stacked, the plurality of pre-preg sheets 402 may be cured.For instance, energy may be applied to the PCB 400 to transition theplurality of pre-preg sheets 402 from the B-stage to a C-stage, bondingthe components of the PCB 400 together.

As discussed above, each of the double-sided laminates 200 includes athermally conductive, electrically insulating additive resin 300 fillingspaces between the electrically conductive material in both thepatterned layers 204, 206 of each of the plurality of double-sidedlaminates 200. As a result, the electrically conductive material of thepatterned layers 204, 206 and the additive resin 300 together formplanar surfaces that contact the plurality of pre-preg sheets 402. Theseplanar surfaces of the double-sided laminates 200 facilitate stackingwith the plurality of pre-preg sheets 402, allowing for only a singlepre-preg sheet 402 to be used to join adjacent double-sided laminates200. For instance, in some embodiments, adjacent double-sided laminates400 may be spaced apart by less than 5 mils, less than 4 mils, or evenless than 3 mils. In particular, the patterned layer 204 of one of thedouble-sided laminates 200 may be spaced less than 5 mils, less than 4mils, or even less than 3 mils away from the patterned layer 206 ofanother one of the double-sided laminates 200. This reduced spacingdecreases the overall thickness of the PCB 400 and increases thermalconductivity of the PCB 400. In one embodiment, the thermal conductivityof PCB 400 in the Z-direction (perpendicular to the planar surfaces justdiscussed) was improved by about 7 percent. In other words, the thermalperformance was about 7 percent more efficient than comparative PCBslacking the additive resin 300. Furthermore, the thermal performance ofthe PCB 400 was also more uniform than comparative PCBs lacking theadditive resin 300 (i.e., hot spots in the PCB 400 were reduced and/oreliminated).

As shown in FIG. 4, two of the plurality of pre-preg sheets 402 eachcontact both the patterned layer 204 of one of the plurality ofdouble-sided laminates 200 and the patterned layer 206 of another one ofthe plurality of double-sided laminates 200. In other embodiments, onepre-preg sheet 402 may contact both the patterned layer 204 of one ofthe plurality of double-sided laminates 200 and the patterned layer 206of another one of the plurality of double-sided laminates 200. In stillother embodiments, three or more pre-preg sheets 402 may each contactboth the patterned layer 204 of one of the plurality of double-sidedlaminates 200 and the patterned layer 206 of another one of theplurality of double-sided laminates 200. In the illustrative embodimentof FIG. 4, two of the plurality of pre-preg sheets 402 contact outersheets 404 of electrically conductive materials.

Referring now to FIG. 5, another illustrative embodiment of a printedcircuit board (“PCB”) 500 according to the present disclosure is shownin cross-section. The PCB 500 is assembled from a plurality of thedouble-sided laminates 100, among other components. While the PCB 500includes three of the double-sided laminates 100 in the illustrativeembodiment of FIG. 5, it is contemplated that the PCB 500 may includeany number of double-sided laminates 100 in other embodiments. Thefeatures of the double-sided laminates 100 are substantially the same asdiscussed above with reference to FIGS. 1 and 3 (as such, the componentparts of the double-sided laminates 100 have not been labelled in FIG. 5so as not to obscure the disclosure). The remaining features of the PCB500, and its assembly, are substantially the same as describe withregard to the PCB 400 of FIG. 4.

Both the PCB 400 and the PCB 500 have specific utility in fabricatingpower supplies, which require high thermal performance in small packages(e.g., quarter-bricks). For instance, the PCBs 400, 500 may be used tofabricate quarter-brick power converters with greater than 95 percentefficiency. By way of example, the PCB 400 (or PCB 500) may be used infabricating a quarter-brick power converter with a power density greaterthan 1000 Watts and an efficiency greater than 97 percent. As anotherexample, the PCB 400 (or PCB 500) may be used in fabricating apoint-of-load buck converter with currents exceeding 80 amps and anefficiency greater than 97 percent.

While certain illustrative embodiments have been described in detail inthe figures and the foregoing description, such an illustration anddescription is to be considered as exemplary and not restrictive incharacter, it being understood that only illustrative embodiments havebeen shown and described and that all changes and modifications thatcome within the spirit of the disclosure are desired to be protected.There are a plurality of advantages of the present disclosure arisingfrom the various features of the methods, systems, and articlesdescribed herein. It will be noted that alternative embodiments of themethods, systems, and articles of the present disclosure may not includeall of the features described yet still benefit from at least some ofthe advantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the methods, systems, andarticles that incorporate one or more of the features of the presentdisclosure.

1. A power supply comprising: a printed circuit board comprising: aplurality of double-sided laminates, each double-sided laminate of theplurality of double-sided laminates comprising (i) an electricallyinsulating core, (ii) a first patterned layer of electrically conductivematerial arranged on a first side of the electrically insulating core,and (iii) a second patterned layer of electrically conductive materialarranged on a second side of the electrically insulating core oppositethe first side; a plurality of thermally conductive, electricallyinsulating pre-preg sheets interleaved with the plurality ofdouble-sided laminates; and a thermally conductive, electricallyinsulating additive resin filling spaces between the electricallyconductive material in both the first and second patterned layers ofeach of the plurality of double-sided laminates, such that theelectrically conductive material and the additive resin together formplanar surfaces that contact the plurality of pre-preg sheets.
 2. Thepower supply of claim 1, wherein each one of the plurality of pre-pregsheets contacts both (i) the first patterned layer of one of theplurality of double-sided laminates and (ii) the second patterned layerof another one of the plurality of double-sided laminates.
 3. The powersupply of claim 2, wherein the first patterned layer of one of theplurality of double-sided laminates is spaced less than 4 mils from thesecond patterned layer of another one of the plurality of double-sidedlaminates.
 4. The power supply of claim 1, wherein each of the pluralityof pre-preg sheets has a thermal conductivity greater than 2Watts/meter-Kelvin.
 5. The power supply of claim 4, wherein theelectrically insulating core of each of the plurality of double-sidedlaminates comprises a cured pre-preg sheet having a thermal conductivitygreater than 2 Watts/meter-Kelvin.
 6. The power supply of claim 4,wherein the additive resin has a thermal conductivity greater than 0.3Watts/meter-Kelvin.
 7. The power supply of claim 4, wherein each of theplurality of pre-preg sheets and the additive resin provides dielectricisolation of at least 500 Volts/mil.
 8. The power supply of claim 1,wherein a thermal performance of the printed circuit board is moreuniform than and at least 7 percent more efficient than another printedcircuit board lacking the additive resin.
 9. The power supply of claim1, wherein the power supply comprises a quarter-brick power converterwith greater than 95 percent efficiency.
 10. A double-sided laminate forfabricating a printed circuit board for a power supply, the double-sidedlaminate comprising: an electrically insulating pre-preg sheet having athermal conductivity greater than 2 Watts/meter-Kelvin; a firstpatterned layer of electrically conductive material arranged on a firstside of the electrically insulating pre-preg sheet; and a secondpatterned layer of electrically conductive material arranged on a secondside of the electrically insulating pre-preg sheet opposite the firstside; wherein a thermally conductive, electrically insulating additiveresin fills spaces between the electrically conductive material in boththe first and second patterned layers, such that the electricallyconductive material and the additive resin together form planar outersurfaces of the double-sided laminate.
 11. The double-sided laminate ofclaim 10, wherein the additive resin has a thermal conductivity greaterthan 0.3 Watts/meter-Kelvin.
 12. The double-sided laminate of claim 11,wherein the pre-preg sheet and the additive resin each providedielectric isolation of at least 500 Volts/mil.
 13. A method forfabricating a printed circuit board for a power supply, the methodcomprising: applying a thermally conductive, electrically insulatingadditive resin to fill spaces between patterned electrically conductivematerial arranged on a first side of a first electrically insulatingcore, such that the electrically conductive material and the additiveresin together form a first planar surface on the first side of thefirst core; applying the additive resin to fill spaces between patternedelectrically conductive material arranged on a second side of a secondelectrically insulating core, such that the electrically conductivematerial and the additive resin together form a second planar surface onthe second side of the second core; contacting the first planar surfacewith a first side of a first thermally conductive, electricallyinsulating pre-preg sheet; and contacting the second planar surface witha second side of the first pre-preg sheet, the second side of the firstpre-preg sheet being opposite the first side of the first pre-pregsheet.
 14. The method of claim 13, further comprising applying energy totransition the pre-preg sheet from a B-stage to a C-stage.
 15. Themethod of claim 13, wherein the first pre-preg sheet has a thermalconductivity greater than 2 Watts/meter-Kelvin.
 16. The method of claim15, wherein the first and second cores are each a C-stage pre-preg sheethaving a thermal conductivity greater than 2 Watts/meter-Kelvin.
 17. Themethod of claim 15, wherein the additive resin has a thermalconductivity greater than 0.3 Watts/meter-Kelvin.
 18. The method ofclaim 17, wherein the first pre-preg sheet and the additive resin eachprovide dielectric isolation of at least 500 Volts/mil.
 19. The methodof claim 13, further comprising: applying the additive resin to fillspaces between patterned electrically conductive material arranged on asecond side of the first electrically insulating core, the second sideof the first core being opposite the first side of the first core, suchthat the electrically conductive material and the additive resintogether form a third planar surface on the second side of the firstcore; applying the additive resin to fill spaces between patternedelectrically conductive material arranged on a first side of the secondcore, such that the electrically conductive material and the additiveresin together form a fourth planar surface on the second side of thesecond core; contacting the third planar surface with a second thermallyconductive, electrically insulating pre-preg sheet; and contacting thefourth planar surface with a third thermally conductive, electricallyinsulating pre-preg sheet.
 20. The method of claim 19, wherein: thefirst, second, and third pre-preg sheets each have a thermalconductivity greater than 2 Watts/meter-Kelvin and each providedielectric isolation of at least 500 Volts/mil; and the additive resinhas a thermal conductivity greater than 0.3 Watts/meter-Kelvin andprovides dielectric isolation of at least 500 Volts/mil.